{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T17:27:57Z","timestamp":1786123677679,"version":"build-2736575974"},"reference-count":45,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T00:00:00Z","timestamp":1786060800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Science and Higher Education of the Republic of Kazakhstan","award":["IRN BR28712529"],"award-info":[{"award-number":["IRN BR28712529"]}]},{"award":["IRN BR28712529"],"award-info":[{"award-number":["IRN BR28712529"]}],"id":[{"id":"https:\/\/ror.org\/05tyne317","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background\/Objectives: Mpox (formerly monkeypox) is a re-emerging global health threat. While current vaccines are injectable, oral vaccination offers a painless alternative, though the harsh gastrointestinal (GI) environment challenges live viral vaccines. This study evaluated the stability of orthopoxviruses under simulated GI conditions to assess the physicochemical feasibility of oral mpox immunization. Methods: Attenuated and virulent strains of vaccinia, cowpox, and camelpox viruses were exposed to simulated gastric (pH 1.0\u20132.0 and 3.0\u20134.0 with pepsin) and intestinal (pH 7.0\u20137.5) conditions at 37 \u00b0C for 180 min. Viral titers were determined via cell culture assays. The physicochemical protective efficacy of enteric-coated capsules was evaluated using standard dissolution testing parameters. Results: All orthopoxviruses were rapidly inactivated under highly acidic fasting conditions (pH 1.0\u20132.0). However, they exhibited high stability at pH 3.0\u20134.0 and 7.0\u20137.5, retaining approximately 20\u201330% of their initial infectivity after 180 min. Enteric-coated capsules successfully maintained shell integrity in simulated gastric fluids for over 3 h and dissolved completely under intestinal conditions within ~130 min, aligning with small intestine transit times. Conclusions: Orthopoxviruses possess sufficient intestinal stability to support the physicochemical feasibility of oral immunization, provided they are protected from gastric acidity. Enteric-coated capsules represent a highly suitable delivery system for the intestinal release of live orthopoxvirus-based candidates, warranting further in vivo preclinical evaluation.<\/jats:p>","DOI":"10.3390\/vaccines14080681","type":"journal-article","created":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T16:00:43Z","timestamp":1786118443000},"page":"681","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Dynamics of Orthopoxvirus Stability Under Simulated Luminal Conditions of the Gastrointestinal Tract for Assessing the Feasibility of Oral Immunization"],"prefix":"10.3390","volume":"14","author":[{"given":"Lespek","family":"Kutumbetov","sequence":"first","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5807-7604","authenticated-orcid":false,"given":"Moldir","family":"Azanbekova","sequence":"additional","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Balzhan","family":"Myrzakhmetova","sequence":"additional","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Moldir","family":"Tuyskanova","sequence":"additional","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aisulu","family":"Valieva","sequence":"additional","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nuraiym","family":"Sarsenkulova","sequence":"additional","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gulzhan","family":"Zhapparova","sequence":"additional","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5363-3501","authenticated-orcid":false,"given":"Dias","family":"Muzarap","sequence":"additional","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Muratbay","family":"Mambetaliyev","sequence":"additional","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sanat","family":"Kilibayev","sequence":"additional","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4238-5116","authenticated-orcid":false,"given":"Kuandyk","family":"Zhugunissov","sequence":"additional","affiliation":[{"name":"Research Institute for Biological Safety Problems LLP, Guardeyskiy 080409, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Alakunle, E., Kolawole, D., Diaz-C\u00e1nova, D., Alele, F., Adegboye, O., Moens, U., and Okeke, M.I. (2024). A comprehensive review of monkeypox virus and mpox characteristics. Front. Cell. Infect. Microbiol., 14.","DOI":"10.3389\/fcimb.2024.1360586"},{"key":"ref_2","unstructured":"World Health Organization (2024). Mpox (Monkeypox): Fact Sheet, WHO."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"100100","DOI":"10.1016\/j.soh.2024.100100","article-title":"Mpox (monkeypox): A comprehensive update of current epidemic evidence","volume":"4","author":"Hossain","year":"2024","journal-title":"Sci. One Health"},{"key":"ref_4","unstructured":"World Health Organization (2026). Multi-Country Outbreak of Mpox: External Situation Reports, WHO."},{"key":"ref_5","unstructured":"World Health Organization (2024). Mpox: Transmission and Prevention, WHO."},{"key":"ref_6","unstructured":"Williams, N. Personal Communication, Materials of the Online Seminar."},{"key":"ref_7","unstructured":"World Health Organization (2025). WHO Strategic Framework for Enhancing Prevention and Control of Mpox, WHO."},{"key":"ref_8","unstructured":"World Health Organization (2024). Mpox Public Health Emergency of International Concern (PHEIC): Recommendations and Prepar-Edness Measures, WHO."},{"key":"ref_9","unstructured":"Ministry of Health of the Republic of Kazakhstan (2025). Scientific and Technical Program Under the Targeted Program Funding Scheme \u201cDevelopment of Diagnostic Tools and Specific Prophylaxis Against Mpox\u201d for 2025\u20132027, Ministry of Health of the Republic of Kazakhstan."},{"key":"ref_10","unstructured":"Fenner, F., Henderson, D.A., Arita, I., Jezek, Z., and Danilovich, I. (1988). Smallpox and Its Eradication\/F. Fenner \u2026 [et al.], World Health Organization. Available online: https:\/\/iris.who.int\/handle\/10665\/39485."},{"key":"ref_11","unstructured":"Jenner, E. (2026, July 01). An Inquiry into the Causes and Effects of the Variolae Vaccinae\u2014London: Sampson Low, 1798. iv, 116 p. NLM Unique ID: 2559001R, Available online: http:\/\/resource.nlm.nih.gov\/2559001R."},{"key":"ref_12","first-page":"559","article-title":"Vaccinia virus and orthopoxvirus vaccines","volume":"9","author":"Baxby","year":"1991","journal-title":"Vaccine"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1007\/s44197-025-00432-8","article-title":"Safety and Efficacy of Repurposed Smallpox Vaccines Against Mpox: A Critical Review of ACAM2000, JYNNEOS, and LC16","volume":"15","author":"Wahid","year":"2025","journal-title":"J. Epidemiol. Glob. Health"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"796","DOI":"10.1080\/14760584.2024.2397006","article-title":"Vaccines against mpox: MVA-BN and LC16m8","volume":"23","author":"Grabenstein","year":"2024","journal-title":"Expert Rev. Vaccines"},{"key":"ref_15","unstructured":"World Health Organization (2024). Vaccines and Immunization for Mpox: Interim Guidance, WHO."},{"key":"ref_16","first-page":"e349","article-title":"Orthopoxvirus Vaccines and Prospects for Prevention of Monkeypox","volume":"15","author":"Shchelkunov","year":"2023","journal-title":"Viruses"},{"key":"ref_17","unstructured":"Tortora, G.J., and Derrickson, B.H. (2018). Principles of Anatomy and Physiology, John Wiley & Sons."},{"key":"ref_18","unstructured":"Agadzhanyan, N.A., Vlasova, I.G., Ermakova, N.V., and Torshin, V.I. (2014). Fundamentals of Human Physiology, Peoples\u2019 Friendship University of Russia (RUDN University). [4th ed.]."},{"key":"ref_19","unstructured":"Akademi\u00e2, T.S., and Vertiprachov, V. (2022). Physiology of Animal Digestion, Russian State Agrarian University\u2014Moscow Timiryazev Agricultural Academy."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1093\/oxfordjournals.aje.a118408","article-title":"A simple method of estimating fifty per cent endpoints","volume":"27","author":"Reed","year":"1938","journal-title":"Am. J. Epidemiol."},{"key":"ref_21","first-page":"415","article-title":"The pH-stability of the elementary bodies of vaccinia","volume":"35","author":"Beard","year":"1938","journal-title":"J. Im.-Munol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"388","DOI":"10.1111\/j.1365-2672.2010.04663.x","article-title":"Isoelectric points of viruses","volume":"109","author":"Michen","year":"2010","journal-title":"J. Appl. Microbiol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1042\/bj2500001","article-title":"Regulation of intracellular pH in eukaryotic cells","volume":"250","author":"Madshus","year":"1988","journal-title":"Biochem. J."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/S0065-3233(08)60460-X","article-title":"Stability of proteins: Small globular proteins","volume":"33","author":"Privalov","year":"1979","journal-title":"Adv. Protein Chem."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/S0165-2478(98)00125-4","article-title":"Vaccinia virus immune evasion","volume":"65","author":"Smith","year":"1999","journal-title":"Immunol. Lett."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1038\/nrmicro1099","article-title":"Poxvirus tropism","volume":"3","author":"McFadden","year":"2005","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1016\/j.vetmic.2009.08.026","article-title":"Zoonotic poxviruses","volume":"140","author":"Essbauer","year":"2010","journal-title":"Vet. Microbiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"597","DOI":"10.1128\/MMBR.62.3.597-635.1998","article-title":"Molecular and Biotechnological Aspects of Microbial Proteases","volume":"62","author":"Rao","year":"1998","journal-title":"Microbiol. Mol. Biol. Rev."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Shchelkunov, S.N. (2013). An Increasing Danger of Zoonotic Orthopoxvirus Infections. PLoS Pathog., 9.","DOI":"10.1371\/journal.ppat.1003756"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Harapan, H., Ophinni, Y., Megawati, D., Frediansyah, A., Mamada, S.S., Salampe, M., Bin Emran, T., Winardi, W., Fathima, R., and Sirinam, S. (2022). Monkeypox: A Comprehensive Review. Viruses, 14.","DOI":"10.3390\/v14102155"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Shchelkunova, G.A., and Shchelkunov, S.N. (2022). Smallpox, Monkeypox and Other Human Orthopoxvirus Infections. Viruses, 15.","DOI":"10.3390\/v15010103"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1111\/lam.12126","article-title":"Environmental persistence of vaccinia virus on materials","volume":"57","author":"Wood","year":"2013","journal-title":"Lett. Appl. Microbiol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1016\/j.addr.2017.04.008","article-title":"Current state and challenges in developing oral vaccines","volume":"114","author":"Sharpe","year":"2017","journal-title":"Adv. Drug Deliv. Rev."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1042","DOI":"10.1126\/science.1219021","article-title":"The Protein-Folding Problem, 50 Years On","volume":"338","author":"Dill","year":"2012","journal-title":"Science"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1111\/j.1863-2378.2007.01035.x","article-title":"Long-Lasting Stability of Vaccinia Virus (Orthopoxvirus) in Food and Environmental Samples","volume":"54","author":"Essbauer","year":"2007","journal-title":"Zoonoses Public Health"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1006\/biol.1999.0236","article-title":"Resistance of Vaccinia Virus to Inactivation by Solvent\/Detergent Treatment of Blood Products","volume":"28","author":"Roberts","year":"2000","journal-title":"Biologicals"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"7551","DOI":"10.1128\/JVI.00016-08","article-title":"Atomic Force Microscopy Investigation of Vaccinia Virus Structure","volume":"82","author":"Kuznetsov","year":"2008","journal-title":"J. Virol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"886","DOI":"10.1136\/gut.27.8.886","article-title":"Transit of pharmaceutical dosage forms through the small intestine","volume":"27","author":"Davis","year":"1986","journal-title":"Gut"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1111\/j.0105-2896.2005.00280.x","article-title":"Oral tolerance","volume":"206","author":"Faria","year":"2005","journal-title":"Immunol. Rev."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"S45","DOI":"10.1038\/nm1213","article-title":"Mucosal immunity and vaccines","volume":"11","author":"Holmgren","year":"2005","journal-title":"Nat. Med."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"893","DOI":"10.1056\/NEJM196810242791701","article-title":"Immunoglobulin Response in Serum and Secretions after Immunization with Live and Inactivated Poliovaccine and Natural Infection","volume":"279","author":"Ogra","year":"1968","journal-title":"N. Engl. J. Med."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1038\/312163a0","article-title":"Expression of rabies virus glycoprotein from a recombinant vaccinia virus","volume":"312","author":"Kieny","year":"1984","journal-title":"Nature"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1056\/NEJMoa2207323","article-title":"Monkeypox Virus Infection in Humans across 16 Countries\u2014April\u2013June 2022","volume":"387","author":"Thornhill","year":"2022","journal-title":"N. Engl. J. Med."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1186\/s13567-017-0459-9","article-title":"Oral vaccination of wildlife using a vaccinia\u2013rabies-glycoprotein recombinant virus vaccine (RABORAL V-RG\u00ae): A global review","volume":"48","author":"Maki","year":"2017","journal-title":"Vet. Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"6781","DOI":"10.1128\/AEM.01658-12","article-title":"Mechanisms by Which Ambient Humidity May Affect Viruses in Aerosols","volume":"78","author":"Yang","year":"2012","journal-title":"Appl. Environ. Microbiol."}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/8\/681\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T16:08:26Z","timestamp":1786118906000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/8\/681"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,7]]},"references-count":45,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["vaccines14080681"],"URL":"https:\/\/doi.org\/10.3390\/vaccines14080681","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,7]]}}}